Hospitalizations Among Adults With CKD in Public Renal Specialty Practices: A Retrospective Study From Queensland, Australia

Rationale & Objective

Little is known about hospital admissions in nondialysis patients with chronic kidney disease (CKD) before death or starting kidney replacement therapy (KRT).

Study Design

Retrospective observational cohort study.

Setting & Participants

Hospitalizations among 7,201 patients with CKD from 10 public renal clinics in Queensland (QLD), enrolled in the CKD.QLD registry starting in May 2011, were followed for 25,496.34 person-years until they started receiving KRT or died, or until June 30, 2018.

Predictors

Demographic and clinical characteristics of patients with CKD.

Outcomes

Hospital admissions.

Analytical Approach

We evaluated the association of demographic and clinical features with hospitalizations, length of hospital stay, and cost.

Results

Approximately 81.5% of the patients were admitted at least once, with 42,283 admissions, costing Australian dollars (AUD) 231 million. The average number of admissions per person-year was 1.7, and the cost was AUD 9,060, 10 times and 2 times their Australian averages, respectively. Single (1-day) admissions constituted 59.2% of all the hospital episodes, led by neoplasms (largely chemotherapy), anemia, CKD-related conditions and eye conditions (largely cataract extractions), but only 14.8% of the total costs. Approximately 41% of admissions were >1-day admissions, constituting 85.2% of the total costs, with cardiovascular conditions, respiratory conditions, CKD-related conditions, and injuries, fractures, or poisoning being the dominant causes. Readmission within 30 days of discharge constituted >42% of the admissions and 46.8% costs. Admissions not directly related to CKD constituted 90% of the admissions and costs. More than 40% of the admissions and costs were through the emergency department. Approximately 19% of the hospitalized patients and 27% of the admissions did not have kidney disease mentioned as either principal or associate causes.

Limitations

Variable follow-up times because of different dates of consent.

Conclusions

The hospital burden of patients with CKD is mainly driven by complex multiday admissions and readmissions involving comorbid conditions, which may not be directly related to their CKD. Strategies to prevent these complex admissions and readmissions should minimize hospital costs and outcomes.

Plain-Language Summary

We analyzed primary causes, types, and costs of hospitalizations among 7,201 patients with chronic kidney disease (CKD) from renal speciality clinics across Queensland, Australia, over an average follow-up of 3.54 years. The average annual cost per person was $9,060, and was the highest in those with more advanced CKD, higher age, and with diabetes. More than 85% of costs were driven by more complex hospitalizations with longer length of stay. Cardiovascular disease was the single largest contributor for hospitalizations, length of hospital stay, and total costs. Readmission within 30 days of discharge, particularly for the same disorder, and multiday admissions should be the main targets for mitigation of hospital costs in this population.

Chronic kidney disease in public renal practices in Queensland, Australia, 2011-2018

AIM

To describe adults with (non-dialysis) chronic kidney disease (CKD) in nine public renal practice sites in the Australian state of Queensland.

METHODS

7,060 persons were recruited to a CKD Registry in May 2011 and until start of kidney replacement therapy (KRT), death without KRT or June 2018, for a median period of 3.4 years.

RESULTS

The cohort comprised 7,060 persons, 52% males, with a median age of 68 yr; 85% had CKD stages 3A to 5, 45.4% were diabetic, 24.6% had diabetic nephropathy, and 51.7% were obese. Younger persons mostly had glomerulonephritis or genetic renal disease, while older persons mostly had diabetic nephropathy, renovascular disease and multiple diagnoses. Proportions of specific renal diagnoses varied >2-fold across sites. Over the first year, eGFR fell in 24% but was stable or improved in 76%. Over follow up, 10% started KRT, at a median age of 62 yr, most with CKD stages 4 and 5 at consent, while 18.8% died without KRT, at a median age of 80 yr. Indigenous people were younger at consent and more often had diabetes and diabetic kidney disease and had higher incidence rates of KRT.

CONCLUSION

The spectrum of characteristics in CKD patients in renal practices is much broader than represented by the minority who ultimately start KRT. Variation in CKD by causes, age, site and Indigenous status, the prevalence of obesity, relative stability of kidney function in many persons over the short term, and differences between those who KRT and die without KRT are all important to explore.

Identification of factors associated with high-cost use of inpatient care in chronic kidney disease: a registry study

OBJECTIVE

To explore factors behind inpatient admissions by high-cost users (HCUs) in pre-end-stage chronic kidney disease (CKD).

DESIGN

Retrospective analysis of CKD.QLD Registry and hospital admissions of the Queensland Government Department of Health recorded between 1 July 2011 and 30 June 2016.

SETTING

Queensland public and private hospitals.

PARTICIPANTS

5096 individuals with CKD who consented to the CKD.QLD Registry via 1 of 11 participating sites.

MAIN OUTCOMES

Associations of HCU status with patient characteristics, pathways and diagnoses behind hospital admissions at 12 months.

RESULTS

Age, advanced CKD, primary renal diagnosis, cardiovascular disease and hypertension were predictors of the high-cost outcome. HCUs were more likely than non-HCUs to be admitted by means of episode change (relative risk: 5.21; 95% CI 5.02 to 5.39), 30-day readmission (2.19; 2.13 to 2.25), scheduled readmission (1.29; 1.11 to 1.46) and emergency (1.07; 1.02 to 1.13), for diagnoses of the nervous (1.94; 1.74 to 2.15), circulatory (1.24; 1.14 to 1.34) and respiratory (1.2; 1.03 to 1.37) systems and other factors influencing health status (1.92; 1.74 to 2.09).

CONCLUSIONS

The high relevance of episode change and other factors influencing health status revealed that a substantial part of excess demand for inpatient care was associated with discordant conditions often linked to frailty, decline in psychological health and social vulnerability. This suggests that multidisciplinary models of care that aim to manage discordant comorbidities and address psychosocial determinants of health, such as renal supportive care, may play an important role in reducing inpatient admissions in this population.

BMI and its association with death and the initiation of renal replacement therapy (RRT) in a cohort of patients with chronic kidney disease (CKD)

Background

A survival advantage associated with obesity has often been described in dialysis patients. The association of higher body mass index (BMI) with mortality and renal replacement therapy (RRT) in preterminal chronic kidney disease (CKD) patients has not been established.

Methods

Subjects were patients with pre-terminal CKD who were recruited to the CKD.QLD registry. BMI at time of consent was grouped as normal (BMI 18.5–24.9 kg/m²), overweight (BMI 25–29.9 kg/m²), mild obesity (BMI 30–34.9 kg/m²) and moderate obesity+ (BMI ≥ 35 kg/m²) as defined by WHO criteria. The associations of BMI categories with mortality and starting RRT were analysed.

Results

The cohort consisted of 3344 CKD patients, of whom 1777 were males (53.1%). The percentages who had normal BMI, or were overweight, mildly obese and moderately obese+ were 18.9, 29.9, 25.1 and 26.1%, respectively. Using people with normal BMI as the reference group, and after adjusting for age, socio-economic status, CKD stage, primary renal diagnoses, comorbidities including cancer, diabetes, peripheral vascular disease (PVD), chronic lung disease, coronary artery disease (CAD), and all other cardiovascular disease (CVD), the hazard ratios (HRs, 95% CI) of males for death without RRT were 0.65 (0.45–0.92, p = 0.016), 0.60 (0.40–0.90, p = 0.013), and 0.77 (0.50–1.19, p = 0.239) for the overweight, mildly obese and moderately obese+. With the same adjustments the hazard ratios for death without RRT in females were 0.96 (0.62–1.50, p = 0.864), 0.94 (0.59–1.49, p = 0.792) and 0.96 (0.60–1.53, p = 0.865) respectively.

In males, with normal BMI as the reference group, the adjusted HRs of starting RRT were 1.15 (0.71–1.86, p = 0.579), 0.99 (0.59–1.66, p = 0.970), and 0.95 (0.56–1.61, p = 0.858) for the overweight, mildly obese and moderately obese+ groups, respectively, and in females they were 0.88 (0.44–1.76, p = 0.727), 0.94 (0.47–1.88, p = 0.862) and 0.65 (0.33–1.29, p = 0.219) respectively.

Conclusions

More than 80% of these CKD patients were overweight or obese. Higher BMI seemed to be a significant “protective” factor against death without RRT in males but there was not a significant relationship in females. Higher BMI was not a risk factor for predicting RRT in either male or female patients with CKD.

Frequency and Consequences of Acute Kidney Injury in Patients With CKD: A Registry Study in Queensland Australia

Background

Acute kidney injury (AKI) contributes to and complicates chronic kidney disease (CKD). We describe AKI documented in hospital encounters in patients with CKD from the CKD Queensland registry.

Study Design

A retrospective cohort study during 2011 to 2016.

Setting & Participants

Participants had been admitted to a hospital in Queensland.

Predictors

AKI was identified from International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification codes.

Outcomes

All-cause mortality with or without kidney replacement therapy (KRT), start-up KRT and maintenance KRT, costs of care.

Analytical Approach

Time to outcomes for those with versus without AKI was evaluated using Cox regression models. Mann-Whitney test was used to compare number of admissions, hospitalized days and costs by AKI status.

Results

Among 6,365 patients followed up for up to 5.4 years, 2,199 (35%) had 4,711 hospital encounters with an AKI diagnosis. Those with AKI were older (68 vs 64 years old), were more often men (36.7% vs 32.2%; P < 0.001), had more advanced CKD stages (stage 3b, 34%; stage 4, 35%; and stage 5, 10%), had more admissions (12 vs 5; P < 0.001), and stayed in the hospital longer (56 vs 14 days; P < 0.001) than those without AKI. Almost 90% of AKI admissions were through the emergency department. Of those with AKI, 554 (25%) subsequently died without any form of KRT and 285 (13%) started KRT, compared with 282 (6.8%) who died and 315 (7.6%) who started KRT among those without AKI; P < 0.001 for each. Adjusted for other significant factors, hazard ratios for all deaths or death without KRT were 2.95 (95% CI, 2.56-3.39; P < 0.001) and 3.02 (95% CI, 2.60-3.51; P < 0.001), respectively, in patients with AKI relative to those without AKI. The hazard ratio for all KRT was 1.40 (95% CI, 1.18-1.66; P < 0.001), and for maintenance KRT was 1.21 (95% CI, 0.98-1.48; P = 0.07). Mean total hospital cost in patients with AKI was more than triple that of patients with no AKI (A $93,042 vs A $30,778; P < 0.001).

Limitations

These findings may not be generalizable to CKD populations from the general community or in other health care environments.

Conclusions

AKI is associated with strikingly increased deaths, increased rates of KRT, and higher hospital costs.

Chronic kidney disease, Queensland: Profile of patients with chronic kidney disease from regional Queensland, Australia: A registry report

BACKGROUND

Chronic kidney disease, Queensland (CKD.QLD) is a multidisciplinary, collaborative research platform for CKD in Queensland. Most public renal services contribute towards the CKD Registry, including Toowoomba Hospital, which is a referral hospital for Darling Downs Health serving a largely regional population in Queensland. We aim to present the profile of the CKD cohort recruited to the CKD.QLD Registry from Toowoomba Hospital, the first comprehensive report on a pre-dialysis population from regional Australia.

METHODS

Study subjects were patients in the Darling Downs Health Service who consented to be included in the CKD.QLD registry from June 2011 to December 2016. Those who were on renal replacement therapy (RRT) were excluded. Patients were followed until date of RRT, death, discharge or loss to follow up or a censor date of 30th June 2017.

RESULTS

Overall 1051 subjects, representing 13% of all CKD.QLD Registry patients gave consent of whom, 42.7% were ≥70 years of age. The mean age was 63.8 ± 15.1 years (median age 67 years) with male predominance (55.4%). The majority were born in Australia (86.4%). Aboriginal and Torre Strait Islanders (A&TSI) constituted 9.6% of the cohort. The predominant CKD stages were 3b (28.9%) and 4 (27.7%). Hypertension and diabetes were noted in 91% and 44% of subjects, respectively. Diabetic nephropathy was the leading cause of CKD (26.7%) followed by renovascular disease (17.3%) and glomerulonephritis (14.8%). In 12%, the diagnosis was uncertain. Major co-morbidities included coronary artery disease (24.7%) chronic lung disease (14.8%), cerebrovascular disease (11.6%) and peripheral vascular disease (8.9%). Non-vascular co-morbidities included arthritis (24.6%), gout (23.6%) and gastro-oesophageal reflux disease (19%). The multi-morbidity profile was differed by gender, diabetic status and age. Over a follow-up period upto 72 months, 93 (8.8%) started RRT and 175 (16.6%) died. Of those 82% died without RRT and 18% died after RRT.

CONCLUSION

This CKD Registry cohort from regional Queensland consisted mainly of older Caucasians with male predominance. A&TSI patients were overrepresented compared to the overall population. A significant proportion had cardio-vascular disease and multiple co-morbidities which differed by gender, diabetic status and age. This report provides valuable data for health services planning and delivery in regional Queensland.

Chronic Kidney Disease, Queensland (CKD.QLD) Registry: Management of CKD With Telenephrology

INTRODUCTION

Enabled by the Chronic Kidney Disease, Queensland (CKD.QLD) Registry, we aim to outline the structure, implementation, and outcomes of telenephrology clinics for the management of patients with chronic kidney disease (CKD) in rural, regional, and remote areas of the Darling Downs region in Queensland, Australia.

METHODS

This is an observational registry-based study involving adult patients with CKD, attending specialist clinics, and residing ≥50 km away from Toowoomba Hospital. The telenephrology cohort (TC) included those who had their follow-up appointments via videoconference at local Queensland Health facilities, and the standard care cohort (SCC) included those who continue to have their follow-up in Toowoomba Hospital.

RESULTS

A total of 234 patients with CKD were seen via videoconference clinics between September 1, 2011 and December 31, 2016, representing 22.2% of the CKD registry cohort from Toowoomba Hospital. The baseline characteristics and comorbid profiles of both groups were similar. The Aboriginal population was overrepresented in the TC (22.2% vs. 5.9%). As a group for each visit, the TC traveled 100,000 km less (both ways) to see a specialist physically. During follow-up, 5.1% of patients in the TC were initiated on dialysis whereas 9.9% were initiated on dialysis in the SCC (P = 0.02). There was lower mortality in the TC (11.1% vs. 18.2%; P = 0.02).

CONCLUSION

Telenephrology clinics were safe, economical, and efficient for the delivery of specialist care for patients with CKD living at a distance from the main referral hospital. Such care was comparable to standard care delivered at the main hospital but with clear benefits to the patients in terms of reduced travel distance, more independence, and similar outcomes.

Body mass index in an Australian population with chronic kidney disease

BACKGROUND

Obesity emerged as the leading global health concern in 2017. Although higher body mass index (BMI) is a health risk in the general population, its implications for chronic kidney disease (CKD) are not entirely clear. Our aim was to compare BMI in an Australian CKD population with BMI in a sample of the general Australian population, and, in the same group of CKD patients, to describe associations of higher BMI categories with demographic and clinical features.

METHODS

A cross-sectional study of BMI in CKD patients was conducted from three major sites who were enrolled in the CKD.QLD registry between May 2011 and July 2015. BMI was categorized according to the World Health Organisation (WHO) guidelines. The prevalence of obesity was compared with a sample of the general Australian population from the most recent National Health Survey (NHS). Associations of BMI with demographic and clinical characteristics of the CKD patients were also analysed.

RESULTS

There were 3382 CKD patients in this study (median age 68, IQR 56-76 years); 50.5% had BMI ≥30, the WHO threshold for obesity, in contrast with 28.4% having BMI ≥30 in the NHS cohort. Higher BMI categories were correlated with age < 70 years, male gender, and lower socioeconomic status. After adjustment for age and gender, characteristics which significantly correlated with higher BMI category included hypertension, dyslipidemia, diabetes, diabetic nephropathy, coronary heart disease, other cardiovascular diseases, gout, obstructive sleep apnoea, depression and chronic lung disease.

CONCLUSIONS

Patients with CKD in public renal specialty practices in Queensland have strikingly higher rates of obesity than the general Australian population. Within the CKD population, low socio-economic position strongly predisposes to higher BMI categories. Higher BMI categories also strongly correlated with important co-morbidities that contribute to burden of illness. These data flag major opportunities for primary prevention of CKD and for reductions in morbidity in people who already have CKD, which should be considered in public health policy in relation to obesity.

CKD Screening and Surveillance in Australia: Past, Present, and Future

Chronic kidney disease (CKD) was largely a hidden health problem until the publication of an internationally agreed approach to its identification, monitoring, and treatment. The 2002 National Kidney Foundation CKD classification and the subsequent 2006 Kidney Disease Improving Global Outcomes (KDIGO) recommendations are powerful tools for translating thinking about CKD into clinical practice. These guidelines were strongly endorsed by the international community, including Australia, and were incorporated into CKD practice guidelines. In the past, CKD research studies in Australia focused on screening the general population, and more specifically, individuals at risk for CKD. Information from these studies led to the recognition that the CKD burden in Australia is a public health problem and contributed to the development of national health policies and priorities. At present, apart from the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) that reports on CKD patients undergoing renal replacement therapy (RRT), long-term surveillance to describe the natural history of the CKD population not on RRT has only recently started. Entities such as CKD. Queensland and the Western Australian Nephrology Database are able to fill the gap and provide opportunities for collaborative research of CKD in Australia. Establishment of a National Health and Medical Research Centre-funded CKD Centre of Excellence in 2015 and the Better Evidence and Translation-Chronic Kidney Disease in 2016 are likely to change the future of CKD surveillance and research in Australia.

CKD.QLD: establishment of a chronic kidney disease [CKD] registry in Queensland, Australia

Background

Chronic kidney disease [CKD] is recognised as a global public health problem. Until recently, the majority of information informing on CKD has been generated from renal registries reporting on patients with end-stage kidney disease [ESKD] and on renal replacement therapy [RRT]. There has been a paucity of information on pre-dialysis CKD cohorts, and many issues related to these poorly described populations are unresolved. To this end, international organizations have called for CKD surveillance systems across all countries.

Description

In Australia, we have responded by developing the Chronic Kidney Disease in Queensland [CKD.QLD] with three main platforms consisting of CKD Registry, clinical trials and development of biobank. This registry which is the core component of CKD surveillance was conceptualized specifically for the pre-dialysis population in the public health system in Queensland, Australia. Recruitment started in May 2011, and to date the Registry has evolved as one of the largest CKD cohorts in the world with recruitment close to 7000 patients. The Registry has had many outcomes, including being the nidus for Australia’s first National Health and Medical Research Council [NHMRC] CKD Centre of Research Excellence [CKD.CRE].

Conclusions

The Registry, with its linkage to Queensland Health datasets, is reporting, and is expected to continue generating, significant information on multiple aspects of CKD, its trajectory, management and patient outcomes. Intent of the CKD.CRE is to facilitate an expanded Registry network that has representation from health services, both public and private, across Australia.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-017-0607-5) contains supplementary material, which is available to authorized users.

Taming the chronic kidney disease epidemic: a global view of surveillance efforts

Chronic kidney disease is now recognized to be a worldwide problem associated with significant morbidity and mortality and there is a steep increase in the number of patients reaching end-stage renal disease. In many parts of the world, the disease affects younger people without diabetes or hypertension. The costs to family and society can be enormous. Early recognition of CKD may help prevent disease progression and the subsequent decline in health and longevity. Surveillance programs for early CKD detection are beginning to be implemented in a few countries. In this article, we will focus on the challenges and successes of these programs with the hope that their eventual and widespread use will reduce the complications, deaths, disabilities, and economic burdens associated with CKD worldwide.

CKD.QLD: chronic kidney disease surveillance and research in Queensland, Australia

BACKGROUND

Chronic kidney disease (CKD) is recognized as a major public health problem in Australia with significant mortality, morbidity and economic burden. However, there is no comprehensive surveillance programme to collect, collate and analyse data on CKD in a systematic way.

METHODS

We describe an initiative called CKD Queensland (CKD.QLD), which was established in 2009 to address this deficiency, and outline the processes and progress made to date. The foundation is a CKD Registry of all CKD patients attending public health renal services in Queensland, and patient recruitment and data capture have started.

RESULTS

We have established through early work of CKD.QLD that there are over 11,500 CKD patients attending public renal services in Queensland, and these are the target population for our registry. Progress so far includes conducting two CKD clinic site surveys, consenting over 3000 patients into the registry and initiation of baseline data analysis of the first 600 patients enrolled at the Royal Brisbane and Women's Hospital (RBWH) site. In addition, research studies in dietary intake and CKD outcomes and in models of care in CKD patient management are underway.

CONCLUSIONS

Through the CKD Registry, we will define the distribution of CKD patients referred to renal practices in the public system in Queensland by region, remoteness, age, gender, ethnicity and socioeconomic status. We will define the clinical characteristics of those patients, and the CKD associations, stages, co-morbidities and current management. We will follow the course and outcomes in individuals over time, as well as group trends over time. Through our activities and outcomes, we are aiming to provide a nidus for other states in Australia to join in a national CKD registry and network.